Method of forming two-dimensional sheet material into three-dimensional structure

ABSTRACT

A two-dimensional sheet material is provided that is suitable for bending along a bend line to form a three-dimensional object. The sheet material is provided with a plurality of displacements in a thickness direction of the sheet material on one side of the bend line. A portion of the displacements shear adjacent the bend line and define an edge and an opposed face. The edge and opposed face configured to produce edge-to-face engagement of the sheet material during bending. Alternatively, sheet material is provided with a plurality of displacements in a thickness direction of the sheet material on one or both sides of the bend line, and with a plurality of corresponding and cooperating protrusions to improve structural integrity and/or to improve electromagnetic and radio frequency shielding. The sheet material may also be provided with a self-latching structure. A method of preparing and using these sheet materials is also described.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 60/854,846 filed Oct. 26, 2006 and entitled SHEET MATERIAL WITH BENDCONTROLLING DISPLACEMENTS, and to U.S. Provisional Patent ApplicationNo. 60/974,473 filed Sep. 23, 2007 and entitled METHOD OF FORMINGTWO-DIMENSIONAL SHEET MATERIAL INTO THREE-DIMENSIONAL STRUCTURE, theentire contents of which applications is incorporated herein by thisreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates, in general, to preparing sheets of material forbending using punching, stamping, roll-forming, and similar processesand then bending the sheets into three-dimensional structures.

2. Description of Related Art

Various methods of preparing sheet materials for precision folding alonga desired bend line have been developed. For example, U.S. Pat. Nos.6,877,349, 6,877,349, 7,032,426, 7,152,449 and 7,152,450 describevarious methods of preparing and folding sheet materials for formingthree-dimensional objects having relatively high tolerances fromsubstantially planar two-dimensional sheets.

The folding-structures shown and described above promote so-callededge-to-face engagement and other phenomena to facilitate folding alonga desired bending line. For example, as discussed in the above-mentioned'450 patent, displacements may be formed to facilitate bending along adesired bend line. In some instances, gaps may be formed between asheared edge of a displacement and an opposing face of the bent sheetmaterial. For example, the gaps may be designed into thebend-controlling structures to further facilitate bending. As anotherexample, the gaps may result from an engineered design to provideclearance during bending or lower manufacturing tolerances. In yetanother example, the gaps may be undesired, and may have resulted fromvarious factors.

The presence of such gaps along the folded edges may present problems.As noted in the above-mentioned '449 patent, certain flat sheets thatare slit or grooved can have electrical components mounted to them using“pick-and-place” techniques. The sheets may then be folded intoenclosures or housings in which all of the components are spatiallyrelated in the desired positions inside the housing. While there isconsiderable advantage to slit-forming or groove-forming techniques, inapplications where shielding is important, gaps along the enclosureedges may lead to electromagnetic (“EM”) waves or radio-frequency (“RF”)signal noise leakage out of the structure.

Additionally, the presence of gaps or pockets along the bend lines may,in some instances, reduce the strength of the folded structure. Forexample, because the gaps decrease the surface contact between edge andface, the folded structure may have less surface area to supportloading. In such cases, it may be desirable to increase the structuralintegrity of the folded product in the gap regions.

In addition, traditional manufacturing techniques often require the useof various fasteners to hold panels of a sheet material in a folded 3Dstructure.

It would therefore be useful to provide a sheet of material havingbend-controlling structures that facilitate precise bending techniques,reduce the gap area near the bend lines, and/or include securingstructures that may reduce the need for fasteners in securing a 2D sheetmaterial into a 3D structure.

DISCLOSURE OF THE INVENTION

One aspect of the present invention is directed to a method of preparinga substantially two-dimensional sheet material for bending along a bendline to form a three-dimensional object. The method includes one or moreof the steps: obtaining a sheet material that is substantiallytwo-dimensional in a region in which a bend is to be made; and forming aplurality of displacements in a thickness direction of the sheetmaterial with a portion of a periphery of the displacement closest tothe bend line shearing to provide the periphery with an edge and anopposed face, the edge and opposed face configured to produceedge-to-face engagement of the sheet material during bending; whereinthe plurality of displacements are located on one side of the bend line.

The forming step may be accomplished by forming at least some of thedisplacements with large-radii ends, wherein a portion of the peripheryof the displacements may diverge from the bend line. The forming stepmay be accomplished by forming a half strap along adjacent divergingportions of the peripheries of adjacent displacements, which half strapsare configured to undergo tension and torsion during bending. Theforming step may be accomplished by forming an intermediate strapportion between adjacent half straps, which half straps are configuredto undergo greater three-dimensional deformation bending during bending.The forming step may be accomplished by forming the periphery of atleast some of the displacements with a non-linear portion intermediatethe large-radii ends.

The forming step may include forming at least one protrusion adjacent tothe bend line and extending in the same direction as a respectivedisplacement, wherein when one panel portion of the sheet material onone side of the bend line may be folded relative to another panelportion on the other side of the bend line, and the protrusion extend toconductively interconnect said one and another panel portions across thebend line. The protrusion may extend from at least one displacement andmay be configured to contact the panel portion of the sheet material onthe other side of the bend line, the method may further include the stepof bending the sheet material to effect contact of the protrusion andthe panel portion on the other side of the bend line. The protrusion mayextend from one panel portion of the sheet material and may beconfigured to contact at least one displacement on the other side of thebend line. The method may further include the step of bending the sheetmaterial to effect contact of the protrusion and the displacement on theother side of the bend line.

The forming step may include forming a securing structure in the sheetmaterial configured to secure one panel portion of the sheet material toanother panel portion of the sheet in a folded position. The method mayfurther include the steps of bending one panel portion of the sheetmaterial about a corresponding bend line and securing said one panelportion to another panel portion of the sheet material with a securingstructure monolithically formed in the sheet material.

Another aspect of the present invention is directed to a method ofpreparing a substantially two-dimensional sheet material for bendingalong a bend line to form a three-dimensional object. The method includeone or more of the steps of: obtaining a sheet material that may besubstantially two-dimensional in a region in which a bend may be to bemade; forming a plurality of displacements in a thickness direction ofthe sheet material with a portion of the periphery of the displacementclosest to the bend line shearing to provide the periphery with an edgeand an opposed face, the edge and face configured to produceedge-to-face engagement of the sheet material during bending; andforming at least one protrusion adjacent to the bend line extending inthe same direction as a respective displacement.

The protrusion may extend from at least one displacement and may beconfigured to contact the panel portion of the sheet material on theother side of the bend line. The method may further include the step ofbending the sheet material to effect contact of the protrusion and thepanel portion on the other side of the bend line. The protrusion mayextend from one panel portion of the sheet material and may beconfigured to contact at least one displacement on the other side of thebend line. The method may further include the step of bending the sheetmaterial to effect contact of the protrusion and the displacement on theother side of the bend line. The protrusion may extend from one panelportion of the sheet material and may be configured to contact at leastone displacement on the other side of the bend line. The method mayfurther include the step of bending the sheet material to effect contactof the protrusion and the displacement on the other side of the bendline. The protrusion may be monolithically formed from the sheetmaterial. The protrusion and a corresponding displacement aresimultaneously formed. A plurality of protrusions may be configured toextend from, or contact, at least one of said displacements. Theprotrusion may extend out-of-plane with respect to a displacement.

In some embodiments, the plurality of displacements are located on oneside of the bend line. The method may further include the steps ofbending one panel portion of the sheet material about a correspondingbend line and securing said one panel portion to another panel portionof the sheet material with a securing structure monolithically formed inthe sheet material.

Still another aspect of the present invention is directed to a method ofpreparing a substantially two-dimensional sheet material for bendingalong a plurality of bend lines to form a three-dimensional objectincluding one or more of the steps: forming a plurality ofbend-facilitating structures in the sheet material along a plurality ofbend lines to form at least a first panel portion and a second panelportion; forming a fastening flange in the first panel portionsubstantially parallel to the second panel portion; and forming afastening receiver in the second panel portion configured to receive aportion of the fastening flange in the first panel portion; forming asecuring button in one of the first and second panel portion and acorresponding securing recess in the other of the first and second panelportions. The fastening flange, the fastening receiver, the securingbutton, and the securing recess may be monolithically formed in thesheet material.

The fastening receiver may be formed with a displaced flap extendingfrom the second panel portion. The fastening receiver may be configuredto receive the fastening flange between the displaced flap and a surfaceof the second panel portion. The fastening flap may be formed with astop edge configured to limit folding movement of the first panelportion relative to the second panel portion and to align the latchbutton with the latch recess. The stop edge may be substantiallyC-shaped. The fastening flap may be formed with a bridge portion underwhich the fastening flap may extend, and wherein the fastening flap maybe formed with a latch surface which forms the latch recess. The bridgeportion may include at least one stop edge configured to limit foldingmovement of the first panel portion relative to the second panel portionand to align the latch button with the latch surface. The bridge portionmay include two diverging stop edges.

Yet another aspect of the present invention is directed to a method ofpreparing a sheet of material for bending along a bend line comprisingthe step of forming a plurality of displacements in the thicknessdirection of the sheet of material with a portion of the periphery ofthe displacement closest to the bend line providing an edge and anopposed face configured and positioned to produce edge-to-faceengagement of the sheet of material during bending, wherein theplurality of displacements are located on one side of the bend line. Theforming step may be accomplished by forming the plurality ofdisplacements with large-radii ends, and a portion of the periphery ofthe displacements remote from the bend line may include a non-linearportion intermediate the large-radii ends.

Still a further aspect of the present invention is directed to a sheetof material suitable for bending along a bend line including a sheet ofmaterial having a plurality of displacements in a thickness direction ofthe sheet of material, a portion of the periphery of the displacementclosest to the bend line providing an edge and an opposed faceconfigured and positioned to produce edge-to-face engagement of thesheet of material on opposite sides of the portion of the peripheryduring bending, wherein the plurality of displacements are located onone side of the bend line. The plurality of displacements may havelarge-radii ends, and wherein a portion of the periphery of thedisplacements remote from the bend line includes a non-linear portionintermediate the large-radii ends.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description of the Invention, which togetherserve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a substantially two-dimensional sheetmaterial having a plurality of folding displacements along a bend line.

FIG. 2 is a perspective view of the two-dimensional sheet material ofFIG. 1 folded into a three-dimensional object.

FIG. 3 is a perspective view of another two-dimensional sheet materialhaving a plurality of folding displacements along a bend line, and FIG.3A is an enlarged plan view of the sheet material shown in FIG. 3.

FIG. 4 is a plan view of an exemplary bend line of the sheet material ofFIG. 1, the bend line having a plurality of displacements on oppositesides thereof.

FIG. 5 is an enlarged view of a portion of the detail of FIG. 4.

FIG. 6 is a cross-sectional view of the sheet material of FIG. 1 takenalong line 6-6 of FIG. 4 and FIG. 5.

FIG. 7 is a cross-sectional view of the sheet material of FIG. 1 shownin a folded position.

FIG. 8 is a cross-sectional view of the sheet material of FIG. 1 shownin another folded position similar to that shown in FIG. 7.

FIG. 9 is an elevational view of another exemplary bend line that may beused with the sheet material of FIG. 1, the bend line having a pluralityof displacements on opposite sides thereof.

FIG. 10 is an elevational view of another exemplary bend line that maybe used with the sheet material of FIG. 1, the bend line having aplurality of displacements on one side thereof.

FIG. 11A and FIG. 11B are elevational views of a three-dimensionalobject similar to that of FIG. 2, including another exemplary securingstructure, the object respectively shown partially and fully folded.

FIG. 12A, FIG. 12B, FIG. 12C and FIG. 12D are elevational views ofanother a three-dimensional object similar to that of FIG. 2 butincluding another exemplary securing structure, the object respectivelyshown in a series of partially and fully folded.

FIG. 13A, FIG. 13B, FIG. 13C and FIG. 13D is a sequence ofcross-sectional views of the object of FIG. 12 taken substantially alongthe line 13-13 in FIG. 12D.

FIG. 14A is a schematic plan view of a displacement utilized in thetwo-dimensional sheet material of FIG. 1, while FIGS. 14A-14J areschematic plan view of alternative displacements for use with the sheetmaterial, and FIGS. 14K-14L are schematic cross-sectional views of thedisplacements of FIGS. 14B-14F and FIGS. 14G-14J, respectively.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to various exemplary embodiments ofthe present invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments, it will beunderstood that the present description is not intended to limit theinvention(s) to those exemplary embodiments. On the contrary, theinvention(s) is/are intended to cover not only the exemplaryembodiments, but also various alternatives, modifications, equivalentsand other exemplary embodiments, which may be included within the spiritand scope of the invention as defined by the appended claims.

Turning now to the drawings, wherein like components are designated bylike reference numerals throughout the various figures, attention isdirected to FIG. 1 and FIG. 2 which disclose an exemplarytwo-dimensional (2D) sheet material 30 that has been dimensioned andconfigured to form a three-dimensional (3D) open box 32. In manyaspects, the exemplary sheet material of the present invention issimilar to that which is described in U.S. Provisional PatentApplication No. 60/665,577 filed Mar. 25, 2005 and U.S. patentapplication Ser. No. 11/386,463 (Pub. No. 2006/0277965), the entirecontents of both applications is incorporated in their entirety by thisreference.

As described in the below-mentioned patents and patent applications,there are numerous applications in which 2D sheet materials can beformed into 3D articles. The depiction of an open box is merelyexemplary; the teachings of the present inventions for precision bendingare also applicable to the production of numerous other 3D articlesincluding, but not limited to, electronic component chasses, automotivecomponents, transport components, construction components, appliancesparts, truck components, RF shields, HVAC components, aerospacecomponents, and more. That is, the teachings of the present applicationare applicable to a wide variety of 3D products and articles that areformed by folding 2D sheet materials.

In many aspects, the sheet materials fold lines and folding straps ofthe present invention are similar to those disclosed by U.S. Pat. No.6,481,259, U.S. Pat. No. 6,877,349, U.S. Pat. No. 7,152,449, U.S. Pat.No. 7,152,450, U.S. patent application Ser. No. 10/821,818 (Pub. No.2005/0005670), U.S. Pat. No. 7,032,426, U.S. patent application Ser. No.10/931,615 (Pub. No. 2005/0097937), U.S. patent application Ser. No.10/985,373 (Pub. No. 2005/0061049), U.S. patent application Ser. No.11/357,934 (Pub. No. 2006/0261139), U.S. patent application Ser. No.10/952,357 (Pub. No. 2005/0064138), U.S. patent application Ser. No.11/384,216 (Pub. No. 2006/0207212), U.S. patent application Ser. No.11/080,288 (Pub. No. 2005/0257589), U.S. patent application Ser. No.11/374,828 (Pub. No. 2006/0213245), U.S. patent application Ser. No.11/180,398 (Pub. No. 2006/0021413), U.S. patent application Ser. No.11/290,968 (Pub. No. 2006/0075798), U.S. patent application Ser. No.11/411,440, U.S. Provisional Patent Application No. 60/665,577, U.S.patent application Ser. No. 11/386,463, and U.S. Provisional PatentApplication No. 60/854,846, the entire contents of which patents andpatent applications are incorporated herein by this reference.

Briefly, the folding of the sheet of materials of the present inventionis largely similar to the methods discussed extensively in theabove-mentioned patent applications and patents, and in particular, the'870 and '726 applications. The main difference is, upon completion offolding, the protrusions of the present invention ensure that there iscontact between both halves of the sheet material across the shear faceof a corresponding displacement, which contact may promoteelectromagnetic interference (“EMI”) and/or radio-frequency interference(“RFI”) shielding and/or enhanced structural integrity.

Sheet material 30 includes a plurality of folding structures 33 formedin the sheet of material that are positioned along a desired fold line35 in a manner similar to that described in the above-mentioned patentsand patent applications. In the illustrated embodiment, the foldingstructures are displacements 37 In some embodiments, the foldingstructures or displacements 37 extend along opposite sides of the bendline 35, as shown in FIG. 1, while in other embodiments, the foldingstructures or displacements 37 a may extend along one side of the bendline 35 a, as shown in FIG. 3. In either case, the folding structuresgenerally define a folding strap 39 which extends across the bend lineinterconnecting panel portions of the sheet material on either side ofthe bend line, that is, interconnecting substantially 2D orsubstantially flat portions on either side of the bend line (e.g., panelportions 30′ and 30″). In some embodiments, the folding strap extendsobliquely across its respective fold line (see, e.g., folding strap 39,FIG. 4), however, the strap need not extend in its entirety across thefold line. The portion of the folding strap which extends obliquelyacross the bend line serves to promote bend-assisting tension andtorsion, in addition to just pure bending, across the bend line asdiscussed below.

Turning to FIG. 4, displacements 37 are formed in sheet of material 30and are positioned along a fold line 35 in a manner similar to thatdescribed in the above-mentioned patents and patent applications. Thedisplacements may be formed by stamping, punching, roll forming and/orother suitable means as is discussed in the '828 application and theother above-mentioned patents and patent applications. The foldingstructures are formed to allow precise folding of the sheet of materialalong the fold lines to ultimately position the sides in closelyabutting relationship and form a 3D structure. One will appreciate thatthe number, position, and relative orientation of the bend lines willvary depending upon the desired shape of the 3D structure.

The displacements, in many respects, are similar to those described inthe above-mentioned '828 application. For example, each displacement 37includes a tongue 40 which is displaced from the overall planar surfaceof sheet material 30. An exemplary embodiment of the tongue is shown inFIG. 5 and FIG. 6. The exemplary tongue has a flat zone 42 extendingsubstantially parallel to the planar portion of the sheet material, andan inclined transition zone 44 extending from the overall planar portionof the sheet material to the flat zone. Preferably the tongue has a flatzone which may lead to increased tool life and other advantages,however, one will appreciate that the tongue need not have a flat zone.

Opposite transition zone 44 is a sheared face 46 that has sheared edges47 extending there along (i.e., the corners formed by the intersectionof sheared face 46 and the planar surfaces of displacement 37). In theillustrated embodiment the sheared edge only extends along one side ofthe displacement, but as described extensively in the above-mentionedpatents and patent application, the actual degree of shearing may vary,if shearing exists at all.

In the illustrated embodiment, the displacements form a substantiallyD-shaped slit in that they have a relatively straight central portion46′ and curved end portions 46″ that diverge away from the bend line.Also, the displacements may be configured to produce edge-to-faceengagement (as described below) in a manner similar to that described inthe above-mentioned patents and patent applications. For example, thesheet material may be configured such that one sheared edge 47 engagesagainst an opposing face 49 during folding (not shown). Alternatively,the sheet material may be configured such that an opposing edge 51engages against sheared face 46 during folding (see, e.g., FIG. 7). Onewill appreciate that the displacements may have other configurationswhich may or may not produce edge-to-face engagement.

Preferably, the curved ends of displacement 37 are relativelylarge-radii ends 53, which radii are greater than the thickness of thesheet material, preferably two or three times greater than the thicknessof the sheet material, and more preferably more than three times thethickness, and even several times as thick. Such a configurationfacilitates “strap” behavior that subjects portions of sheet materialimmediately adjacent the large-radii ends, which portions are generallyreferred to as a half-straps 54, to tension and torsion (see, e.g., FIG.3A). These portions immediately adjacent the ends generally experiencegreater stress and deformation during bending. Using the half strapsserve to realign such stresses and deformations to reduce, minimize,and/or prevent propagation of shear through strap 39 during bending, aswell as during subsequent vibrations and cyclical or simple loading. Thehalf straps may also serve to facilitate precision bending along thebend line.

Portions of the sheet material intermediate the half-straps generallyundergo greater pure bending with relatively less torsion, as comparedto the portions immediately adjacent the ends of the displacement. Inparticular, extending between adjacent half-straps 54 are intermediatestrap portions or mid zones 56 that are relatively removed fromlarge-radii ends but lying between two adjacent large-radii ends. Theseintermediate portions are generally subjected to more pure bending, thatis, bending of the structure which results in compression along internalsurfaces along the bend line and tension along external surfaces alongthe bend line with minimal torsion. In contrast, the half straps aregenerally subjected to relatively high tension and torsion but subjectedto relatively less pure bending, or possibly minimal pure bending or nopure bending. As such, one will appreciate that the lengths of theintermediate portions may be vary as the half straps may primarily beresponsible for facilitating precision bending along the bend line.Advantageously, longer intermediate portions may result in a reducednumber of displacements required along a bend line, increased areas ofmaterial interconnecting portions of sheet material on either side ofthe bend line, and/or other advantages.

Turning now to FIG. 7 and FIG. 8, in some instances, a gap may formbetween sheared face 46 and the opposing edge 51 when a 2D sheetmaterial 30 is folded into a 3D box 32 or other object. While in somecases, such gaps may be desired and designed into the fold line, inother cases, the gaps may be unintentional and/or undesired.

In some instances, radio-frequency (“RF”) leakage may be a concern. Forexample, when the bending technology described in the above-mentionedpatents and patent applications is used to form RF shields, such gapsmay create a corner joint or intersection in which gaps of unconnectedmaterial, that is, gaps between panel portions of the sheet material oneither side of the bend line are of sufficient length that the gapsallow for undesirable RF leakage. In other instances, the 3D object maybe a load bearing object, in which case, gaps of significant length maybe sufficiently long to decrease the structural integrity of the 3Dobject.

Referring again to FIG. 4 et seq., sheet of material 30 may be providedwith nipples 58 or other types of protrusions in order to diminish theundesirable effects of such gaps 60. Preferably the protrusions aremonolithically formed with the sheet material, and more preferably,stamped, punched, roll-formed or otherwise formed simultaneously withthe corresponding displacement. The protrusions may be formed in thesame step or sequentially with the displacement. One will appreciate,however, that the protrusions may be discrete and attached to the sheetmaterial (or displacement) by suitable means. In the instances where RFleakage is a concern, it is preferred that the protrusions areelectrically conductive with the sheet material. One will furtherappreciate that when gaps and/or RF leakage is not a concern, the sheetmaterial may be formed without the protrusions (see, e.g., FIG. 4).

The protrusions are dimensioned and configured to reduce effectivelength of edge-to-face gaps 60 by extending across the gap and abuttingagainst a portion of sheet material 30 on the other side of the bendline. For example, FIG. 7 illustrates protrusion 58 engaging against theupper planar surface of tongue 40, while FIG. 8 illustrates a protrusion58 that abuts engages against sheared face 46. The protrusions projectfrom the sheet on an opposite side of the bend line as a respectivedisplacement and, as the protrusion is located approximately even withthe mid point of the corresponding sheared face, effectively cuts theeffective length of the gap by one-half. In this manner, gap 60 may beat least partially “closed” to reduce or prevent RF leakages. Also, theabutting configuration of protrusion-against-tongue may providestructural support. For example, protrusion 58 in FIG. 7 would limitupward movement of tongue 40 relative to the protrusion 58 (see, e.g.,arrow “U”), while the protrusion in FIG. 8 would limit leftward movementof the tongue relative to the protrusion (see, e.g., arrow “L”). Assuch, protrusion 58 may support displacement 37 in a direction in whichthe displacement would otherwise be free to move. To further enhancestructural support, multiple protrusions may be provided between strap,as discussed below.

In another embodiment, the protrusion may be provided on the tongue suchthat the protrusion extends across the bend line and thus ensurescontact across the bend line. For example, FIG. 9 illustrates a numberof protrusions 58 b located on displacements 37 b. As can be seen in thefigure, one, two, three or more protrusions may be provided on thedisplacements. Also, protrusions may be provided on adjacentdisplacements, or not. In the embodiments of FIG. 9, each displacement37 b is formed in a downward direction with a downwardly slopinginclined transition region 44 b, and each protrusion 58 b extendsdownwardly from flat portion 42 b. In one embodiment, each protrusion ispositioned at an end of a tongue along a sheared edge.

As shown in FIG. 10, protrusions 58 c may extend from a substantiallystraight sheared face 46 c, however, the protrusions may have otherconfigurations and still be effective to reduce the effective length ofthe gap. For example, the protrusion may be in the form of aoutwardly-bowed sheared face 46 d, or may be in the form of an scallopedface 46 e. Also, the protrusions appear to be as effective in “closing”the gap for displacements arranged along one side of the bend line, asshown in FIG. 10, as they are for displacement arranged along both sidesof the bend line, as shown in FIG. 9.

Referring now to FIG. 9, one will appreciate that protrusions extendingfrom a displacement may extend out-of-plane from the displacement. Forexample, protrusions 58 f may extend above or below the correspondingdisplacement 37 f.

One skilled in the art will understand that the protrusions may have avariety of shapes, sizes, configurations, and positions in the foldingstructure as necessitated by the application. Such application factorsinclude, but are not limited to, the folding characteristics andmanufacturing and design specifications for the three-dimensionalstructure to be formed. As shown in FIG. 9 and FIG. 10, the shapes andsizes of the protrusions may also vary from displacement to displacementalong a bend line. Also, various manufacturing specifications may alsodictate the desired size, shape, and configuration of the protrusions.

Turning now to FIG. 11A and FIG. 11B, various methods of securing the 2Dsheet material into a 3D shape may be utilized in accordance with thepresent invention. Securing structures and other latches may be providedto fasten one panel portion of the sheet material to another panelportion of the sheet material to form the 3D structure. In an exemplaryembodiment, securing structure 61 guides and secures a folding orswinging side 63 to one or more stationary sides 65. The folding side isprovided with a fastening flange 67 while the stationary side isprovided with a cooperating fastening flap 68 that receives and guides aportion of the fastening flange such that latch button 70 will engagewith latch opening 72. In the exemplary embodiment, the opening isactually an outward displacement which creates a recess that receivesthe latch button to latch swinging side 63 in place relative tostationary side 65. In such cases, it is preferred that the shearededges of the button (e.g., 70′) and the opening (e.g., 72′) are directedaway from the swinging side to ensure positive latching. In particular,the fastening flap is dimensioned and configured to receive a runningedge 74 of fastening flange 67 and hold the fastening flange in aposition closely abutting against the surface of stationary side 65. Inthe exemplary embodiment, the fastening flap is provided with anoptional stop edge 75 which is configured to limit movement of thefolding side inward, as is stop edge 75′ on the fastening flange, andthus facilitates engagement of the latch button and latch opening.

As can be seen from the figures, the components of securing structure 61may be formed by stamping, punching, roll-forming, and/or other suitablemeans. Accordingly, the securing structure may be formed simultaneously,or sequentially, with the bend-facilitating displacements discussedabove. One will further appreciate that the illustrated securingstructure may be monolithically formed from the sheet material. As such,one will also appreciate that the securing structure may be used tosecure folded panel portions of the sheet material together without theneed for additional or discrete fasteners. Accordingly, the securingstructures of the present invention not only reduce part count and itsassociated costs, but may also facilitate quality and accuracy reducingproduct cost while also facilitating assembly and thus reduce labor andits associated time and costs.

In still another exemplary embodiment of the present invention shown inFIG. 12 and FIG. 13, securing structure 61 g is similar to thatdescribed above but includes a bridge 77 through which a leading edge 79of fastening flange 67 g extends. In the illustrated embodiment, latchbutton 70 g is provided on fastening flange 67 g and, instead of a latchopening, the bridge is provided with a latch surface 81. One willappreciate that the bridge may also be used with the latch button andlatch opening of the above-described embodiment.

In a manner similar to that described above, bridge flap 77 guides thefastening flange 67 g of swinging side 63 g into position such thatleading edge 79 of fastening flange extends under the bridge flap and issandwiched between the bridge flap and the planar surface of stationaryside 65. Like the displacements described above, latch button may beformed by stamping, punching, roll-forming and/or other suitable means.As such, the latch button has ramped edge 82 that facilitates insertionof the leading edge 79 and latch button 70 under the bridge. Inparticular, the ramped edge will bias bridge portion 77 outwardly (see,e.g., FIG. 12C and FIG. 13C) until the latch button passes beyond latchsurface 81. Once in the folded position, bridge 77 is configured to snapback to its original position such that latch the button opening engagesagainst the latch surface to prevent the folding side from folding awayfrom the stationary side, as shown in FIG. 12C and FIG. 13C. Preferably,the latch surface and latch button have corresponding shapes such thatthe clasp is secured in the opening with reduced movement.

One will appreciate that the securing structures may have other suitableconfigurations. For example, the latch button 70 could configured anddimensioned such that it descends into the void left by displacementunder bridge portion 77.

The free edge of the latch button abuts a front edge of the bridgeportion to positively secure the fold into place in the lateraldirection. In order to open the structure, a user lifts the bride andpushes on the latch button to pass it back under the bridge portion. Inkeeping with the spirit of the invention, one skilled in the art willunderstand that the securing mechanism and structures may have a varietyof shapes, sizes, configurations, and positions in the sheet of materialas necessitated by the application. The securing structures act toposition and optionally secure a folded side of a sheet of material ofthe present invention into position. In this manner, the securingstructures act not only to facilitate folding but also to addedstructure integrity to the folded structure.

In other exemplary embodiments of the present invention, alternativelyshaped displacements may be utilized, such as those shown in FIGS.14A-J. For example, displacement 37 h is similar to displacement 37described above in that flat zone 42 h still has a linear portionextending along the bend line, however, the portion of the flat zoneremote from the bend line has a non-linear geometry, and a similarlyshaped transition zone 44 h. In operation and use, displacement 37 h isused in substantially the same manner as displacement 37 as the linearportion still engages the sheet material on the other side of the bendline in a manner similar to that discussed in the above-mentioned '828application.

For convenience in explanation and accurate definition in the appendedclaims, the terms “up” or “upper”, “down” or “lower”, “inside” and“outside” are used to describe features of the exemplary embodimentswith reference to the positions of such features as displayed in thefigures.

In many respects various modified features of the various figuresresemble those of preceding features and the same reference numeralsfollowed by subscripts “a” through “g” designate corresponding parts.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable others skilled in the art to make andutilize various exemplary embodiments of the present invention, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the invention be defined by the Claims appended hereto andtheir equivalents.

1. A method of preparing a substantially two-dimensional sheet materialfor bending along a bend line to form a three-dimensional object, themethod comprising the steps of: obtaining a sheet material that issubstantially two-dimensional in a region in which a bend is to be made;and forming a plurality of displacements in a thickness direction of thesheet material with a portion of a periphery of the displacement closestto the bend line shearing to provide the periphery with an edge and anopposed face, the edge and opposed face configured to produceedge-to-face engagement of the sheet material during bending; whereinthe plurality of displacements are located on one side of the bend line.2. A method according to claim 1, wherein the forming step isaccomplished by forming at least some of the displacements withlarge-radii ends, and wherein a portion of the periphery of thedisplacements diverge from the bend line.
 3. A method according to claim2, wherein the forming step is accomplished by forming a half strapalong adjacent diverging portions of the peripheries of adjacentdisplacements, which half straps are configured to undergo tension andtorsion during bending.
 4. A method according to claim 3, wherein theforming step is accomplished by forming an intermediate strap portionbetween adjacent half straps, wherein the intermediate strap portion isconfigured to undergo greater pure bending than the half straps duringbending.
 5. A method according to claim 2, wherein the forming step isaccomplished by forming the periphery of at least some of thedisplacements with a non-linear portion intermediate the large-radiiends.
 6. A method according to claim 1, wherein the forming stepincludes forming at least one protrusion adjacent to the bend line, theprotrusion extending in the same direction as a respective displacement,wherein when one panel portion of the sheet material on one side of thebend line is folded relative to another panel portion on the other sideof the bend line, the protrusion interconnects said one and anotherpanel portions across the bend line.
 7. A method according to claim 6,wherein the protrusion extends from at least one displacement and isconfigured to contact the panel portion of the sheet material on theother side of the bend line, the method further including the step ofbending the sheet material to effect contact of the protrusion with thepanel portion on the other side of the bend line.
 8. A method accordingto claim 6, wherein the protrusion extends from one panel portion of thesheet material and is configured to contact at least one displacement onthe other side of the bend line, the method further including the stepof bending the sheet material to effect contact of the protrusion andthe displacement on the other side of the bend line.
 9. A methodaccording to claim 1, wherein the forming step includes forming asecuring structure in the sheet material that is configured to secureone panel portion of the sheet material to another panel portion of thesheet in a folded position.
 10. The method according to claim 1, furthercomprising the steps of bending one panel portion of the sheet materialabout a corresponding bend line and securing said one panel portion toanother panel portion of the sheet material with a securing structuremonolithically formed in the sheet material.
 11. A sheet material formedby the method of claim
 1. 12. A three-dimensional object formed with thesheet material of claim
 11. 13. A product incorporating thethree-dimensional object of claim
 12. 14. A method of preparing asubstantially two-dimensional sheet material for bending along a bendline to form a three-dimensional object, the method comprising the stepsof: obtaining a sheet material that is substantially two-dimensional ina region in which a bend is to be made; forming a plurality ofdisplacements in a thickness direction of the sheet material with aportion of the periphery of the displacement closest to the bend lineshearing to provide the periphery with an edge and an opposed face, theedge and face configured to produce edge-to-face engagement of the sheetmaterial during bending; and forming at least one protrusion adjacent tothe bend line extending in the same direction as a respectivedisplacement.
 15. A method according to claim 14, wherein the protrusionextends from at least one displacement and is configured to contact thepanel portion of the sheet material on the other side of the bend line,the method further including the step of bending the sheet material toeffect contact of the protrusion and the panel portion on the other sideof the bend line.
 16. A method according to claim 14, wherein theprotrusion extends from one panel portion of the sheet material and isconfigured to contact at least one displacement on the other side of thebend line, the method further including the step of bending the sheetmaterial to effect contact of the protrusion and the displacement on theother side of the bend line.
 17. A method according to claim 16, whereinthe protrusion extends from one panel portion of the sheet material andis configured to contact at least one displacement on the other side ofthe bend line, the method further including the step of bending thesheet material to effect contact of the protrusion and the displacementon the other side of the bend line.
 18. A method according to claim 14,wherein the protrusion is monolithically formed from the sheet material.19. A method according to claim 14, wherein the protrusion and acorresponding displacement are simultaneously formed.
 20. A methodaccording to claim 14, wherein a plurality of protrusions are configuredto extend from, or contact, at least one of said displacements.
 21. Amethod according to claim 14, wherein the protrusion extendsout-of-plane with respect to a displacement.
 22. A method according toclaim 14, wherein the plurality of displacements are located on one sideof the bend line.
 23. The method according to claim 14, furthercomprising the steps of: bending one panel portion of the sheet materialabout a corresponding bend line; and securing said one panel portion toanother panel portion of the sheet material with a securing structuremonolithically formed in the sheet material.
 24. A sheet material formedby the method of claim
 23. 25. A three-dimensional object formed withthe sheet material of claim
 24. 26. A product incorporating thethree-dimensional object of claim
 25. 27. A method of preparing asubstantially two-dimensional sheet material for bending along aplurality of bend lines to form a three-dimensional object, the methodcomprising the steps of: forming a plurality of bend-facilitatingstructures in the sheet material along a plurality of bend lines to format least a first panel portion and a second panel portion; forming afastening flange in the first panel portion substantially parallel tothe second panel portion; and forming a fastening receiver in the secondpanel portion configured to receive a portion of the fastening flange inthe first panel portion; forming a securing button in one of the firstand second panel portion; and a corresponding securing recess in theother of the first and second panel portions; wherein the fasteningflange, the fastening receiver, the securing button, and the securingrecess are monolithically formed in the sheet material.
 28. A methodaccording to claim 27, wherein the fastening receiver is formed with adisplaced flap extending from the second panel portion, and wherein thefastening receiver is configured to receive the fastening flange betweenthe displaced flap and a surface of the second panel portion.
 29. Amethod according to claim 28, wherein the fastening flap is formed witha stop edge configured to limit folding movement of the first panelportion relative to the second panel portion and to align the latchbutton with the latch recess.
 30. A method according to claim 29,wherein the stop edge is substantially C-shaped.
 31. A method accordingto claim 28, wherein the fastening flap is formed with a bridge portionunder which the fastening flap extends, and wherein the fastening flapis formed with a latch surface which forms the latch recess.
 32. Amethod according to claim 31, wherein the bridge portion includes atleast one stop edge configured to limit folding movement of the firstpanel portion relative to the second panel portion and to align thelatch button with the latch surface.
 33. A method according to claim 31,wherein the bridge portion includes two diverging stop edges.
 34. Asheet material formed by the method of claim
 27. 35. A three-dimensionalobject formed with the sheet material of claim
 27. 36. A productincorporating the three-dimensional object of claim 27.